Which of the following is not an example of evolution that has resulted from human activity?

Because of hunting, species such as bears and wolves are in danger of extinction

What is the difference between a tissue and an organ system?

An organ system includes tissues.

The tree in your backyard is home to two cardinals, a colony of ants, a wasp's nest, two squirrels, and millions of bacteria. Together, all of these organisms represent

a community

A scientist performs a controlled experiment. This means that

the two experiments are conducted, one differing from the other by only a single variable

The ultimate source of energy flowing into nearly all ecosystems is

sunlight

Kingdom Fungi includes species

that obtain food by decomposing dead organisms and absorbing the nutrients.

Your instructor ask you to look into your microscope to see a prokaryotic cell. You will be looking for a cell that

has a membrane

An antibiotic kills 99.9% of bacterial population. You would expect the next generation of bacteria

to be more resistant to the antibiotic.

Which of the following statements about genetics is true?

Differences among organisms reflect different nucleotide sequences in their DNS.

In an ecosystem, energy

typically flows from consumers to producers to decomposers.

Members of the kingdom Animalia

make their own food through photosynthesis

The teeth of grain-eating animals (such as horses) are usually broad and ridged. This makes the teeth suitable for grinding and chewing. Meat-eating animals (such as lions) have pointed teeth that are good for puncturing and ripping flesh. This illustrates

a result of natural selection as well as the connection between form and function.

Which of the following statements about the properties of life is false

All organism have the ability to maintain a constant internal temperature

WHich of the following is not an example of evolution that has resulted from human activity.

Becasue of hunting, species such as bears and wolves are in danger of extiction

Biology is one of the seven properties that we associate with life.

False

DNA allows us to identify common genes across different species.

True

An ecosystem is made up of all the organisms living an a given area

False

The taxonomic category below the kingdon level is called a domain

False

All of the individuals within a species living in the same geographical area are called a population

True

The biosphrere is the sum of all ecosystems

True

The heart is an example of an organ system

False

Eu is a prefix that means false

False

System biology studies interactions amonf "parts" within biology

True

A prokayotic cell has a membrane-bound nucleus

False

The goal of technology is to apply scientific knowledge for a specific purpose

True

A gene is a unit of hereditary

True

Bacteria are prokaryotes

True

Producers are consumers

False

A controlled experiement can have no more than two variables

False

Emergent properties are new properties that arise with each step upward in the hierarchy of life

True

An organelle performs a specific function within a tissue

False

Archaea is one of two eukaryotic domains of life, the other being Bacteria

False

Individuals with naturally selected traits are less likely to survive

False

A molecule is made up of two or more atoms held together by bonds

True

All organisms are composed of eukaryotic cells

False

A theory is an explanation of an idea that is narrower in scope than a hypothesis

False

Ell is a prefix that means small

True

A gene is a unit of hereditary

True

Evolution explains the unity and diversity of life.

True

In an ecosystem, a consumer exclusively eats other animals

False

Clot formation in our blood can lead to a heart attack or stroke. What was altered in the proteins that made the clot?

The proteins were no longer soluble in the blood

What is the fundamental difference between covalent and ionic bonding

In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts electrons from the other

Which of the following statements about pH is true?

An increase in hydrogen ion concentration means a decrease in pH scale units.

Which of the following particles is found in the nucleus of an atom?

protons and neutrons

You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which of the following statements is true?

You've just prepared an aqueous solution.

In some areas, fluoride is added during the municipal water treatment process in order to help

reduce tooth decay

Which of the following trace elements needed by humans is commonly added to table salt?

iodine

Compared to a solution of pH 3, a solution of pH 1 is

100 times more acidic

Which of the following hypotheses would be supported if liquid water were found on Mars and contained evidence of bacteria-like organisms?

The chemical evolution of life is possible

A water molecule (HOH) is held together by

t

Which of the following statements about radioactive isotopes is true?

The energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells.

Which of the following would be considered an effective way to decrease the production of acid precipitation?

Whenever possible, walk or ride a bicycle instead of driving a car

In the equation 2 H2 + O2 → 2 H2O, the H2 molecules are ________ and the H2O molecules are ________.

reactants . . . products

The body uses atoms in different ways to accomplish different tasks. For example, one portion of the body's calcium supply strengthens bones, whereas another portion combines with proteins to stimulate blood clotting after tissue injury. Which of the statements that follow provides the most logical chemical explanation of calcium's ability to perform such different functions?

The bone contains calcium salts, which are less reactive than the calcium ions found in the blood

Typically, nitrogen atoms are composed of electrons, protons, and neutrons. An isotope of nitrogen could

have more neutrons than the usual nitrogen atom.

Water molecules stick to other water molecules because

hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules

Which of the following is dependent on the ability of water molecules to form hydrogen bonds with other molecules besides water?

the universality of water as a solvent

The temperature of evaporation is much higher for water than for alcohol. Without knowing more about the chemistry of alcohol, which of the following is the most logical chemical explanation for this phenomenon?

Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break away from solution and enter the air.

The tendency of water molecules to stick together is referred to as

cohesion

What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?

12

________ are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bonds within and around large molecules.

Hydrogen bonds

The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium

23

A(n) ________ forms when two atoms share electrons.

covalent bond

The reactants are found on the right side of the arrow in a chemical equation

False

A positively charged subatomic particle is called a proton.

True

Each water molecule can form hydrogen-bonds with as many as four partners because of its polarity.

true

Oxygen forms a double bond because it shares two pairs of electrons.

True

The pH scale of 2-10

False

An aqueous solution is always ionic.

False

An aqueous solution is always ionic

False

H2 and H2O are examples of molecules.

True

The total number of protons, neutrons, and electrons equals the atomic number.

false

O2 is an example of a compound.

False

The atomic mass is approximately equal to the atomic number

True

When a compound gains or loses one or more electrons resulting in an electrical charge it is called an ion.

False

On the pH scale, a 10 would be a base while water would be a 0.

False

Acid precipitation of rain, snow, or fog has a pH of 5.6 or higher.

False

An acid has a low concentration of H+ in solution

False

The environment affects the strength of an ionic bond.

True

There are about 45 elements essential to life.

False

A buffer allows changes in the pH of a solution to occur more easily.

False

A solution is a liquid consisting of two or more substances uniformly mixed

True

A neutron’s charge helps to hold the electrons near the nucleus.

false

Water is an excellent solute.

False

The energy given off from radioactive isotopes can damage cellular molecules causing serious risks to living organisms.

True

Hydrogen bonds give water an unusually high surface tension making it behave as if it is coated with an invisible film.

True

H2 and H2O are examples of polar covalent bonds.

False

The ending material in a chemical reaction is referred to as the product.

True

On the pH scale, a 10 would be a base while water would be a 0.

False

A base is a compound that accepts hydrogen ions and removes them from solution, lowering its H+.concentration.

True

The reactants are found on the right side of the arrow in a chemical equation.

False

Heat is the amount of energy that is associated with movement of atoms and molecules in a body of matter.

True

Matter is anything that occupies space and has mass.

True

A positively charged subatomic particle is called a proton.

True

Each electron travels in its own orbital within an electron shell.

True

An electron is slightly smaller than a proton or neutron

True

Fluorine and iron are examples of trace elements

True

An element is a substance that can only be broken down by other substances by ordinary chemical means.

False

A neutron’s charge helps to hold the electrons near the nucleus.

False

Salt is a common solvent.

False

Temperature measures the average speed of molecules in a body of matter.

True

H2 and H2O are examples of molecules.

True

Chemical bonds enable compounds to fill their outer shell

False

Which of the following organisms contain the polysaccharide chitin?

fungi and insects

Propanol and isopropanol are isomers. This means that they have

the same molecular formula, but different chemical properties.

A major type of lipid found in cell membranes is

phospholipids

Proteins differ from one another because

A. the sequence of amino acids in the polypeptide chain differs from protein to protein.

A diet high in animal products and hydrogenated vegetable margarine may increase the risk for atherosclerosis. This is because

most animal fats are saturated and many hydrogenated vegetable margarines contain high levels of trans fats.

Lactose intolerance

does not affect the consumption of beverages made from soy or rice.

Which of the following is an example of secondary structure in a protein?

an alpha helix

Which of the following statements about enzymes is false?

They are monomers used to build proteins.

High-fructose corn syrup is made from corn. The main carbohydrate in corn is a polysaccharide called

Starch

A disaccharide forms when

two monosaccharides join by dehydration synthesis.

Which of the following statements about animal cell lipids is false?

Many lipids function as enzymes.

Mad cow disease serves as an example of how interdependent ________ and ________ are to protein.

structure . . . function

A carbon skeleton may be branched or unbranched.

true

All hydrocarbons contain carbon, hydrogen, and oxygen.

False

Synthetic variants of testosterone are called anabolic steroids

T

The monomers that make up a nucleotide is made up of three parts: a sugar, a phosphate group and one of eight different nitrogenous bases

F

Compounds with phosphate groups are often involved in energy transfer.

T

Cholesterol is necessary for the production of steroids.

T

Monosaccharides and polysaccharides are phospholipids

F

A fat is made up of three glycerol and one fatty acid molecule

F

Most enzymes end with ase

T

Glycogen is stored as crystals in the liver and muscle cells and broken down when energy is needed.

T

Monosaccharides and polysaccharides are lipids

F

A gene is a discrete unit of inheritance, composed of deoxyribonucleic acid

T

A chain of amino acids is referred to as a polypeptide

T

The expression of a gene is affected by the addition of a methyl group to a component of DNA.

T

A very high fever causes denaturation, interfering with body functions

T

Carbohydrate monomers are called monosaccharides

T

Genes consist of polymers called nucleic acids

T

Chitin is a monosaccharide used by crustaceans to build their hard exoskeleton.

F

Animal cell membranes contain cholesterol

T

Compounds with carbonyl groups are called carboxylic acids.

F

As monomers are linked together they release a water molecule in what is referred to as a dehydration reaction

T

Compounds with phosphate groups are often involved in energy transfer.

T

A gene is a discrete unit of inheritance, composed of deoxyribonucleic acid.

T

A fat is made up of three glycerol and one fatty acid molecule

F

Genes consist of polymers called nucleic acids

T

If a protein loses it shape it loses its function.

T

Glycogen is stored as crystals in the liver and muscle cells and broken down when energy is needed

T

DNA and RNA are nucleic acids.

T

Compounds with carbonyl groups are called carboxylic acids

F

Sugars contain a carbonyl group

t

Ribonucleic acid is used to copy sections of DNA and produce proteins

t

The cellulose in cotton bath towels is hydrophilic, allowing it to absorb water well

t

Cholesterol is necessary for the production of steroids

t

Polar compounds tend to be hydrophilic.

t

The expression of a gene is affected by the addition of a methyl group to a component of DNA

t

A chain of amino acids monomers forms a protein.

t

An amino group acts as a base by picking up H- from a solution

f

Carbohydrates are the main fuel for the body’s cells

t

A chain of amino acids is referred to as a polypeptide

t

The endosymbiosis hypothesis is supported by all of the following pieces of evidence, except the fact that

When a cell is deprived of oxygen, its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will

undergo self-digestion and die

Protein synthesis requires the use of mRNA, which

is translated by the ribosomes into the amino acid sequences of proteins

Which of the following statements about internal membranes in eukaryotic cells is false?

. In eukaryotic cells, internal membranes provide an additional area for many metabolic processes to occur.

Which location in the cell is unlikely to contain ribosomes or ribosomal subunits?

plasma membrane

Cilia differ from flagella in that

cilia are typically more numerous and shorter than flagella

Contractile vacuoles

prevent cells from bursting as a result of the influx of excess water.

Dynein feet

are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets

A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which of the following instruments would be best, and why?

a light microscope, because it allows observations of whole, live cells

Cyanide inhibits mitochondrial function; as a result, the rate of

ATP synthesis decreases

A woman is having trouble becoming pregnant. Examination of her partner's sperm indicates that dynein feet are missing from the flagella in his sperm cells. A physician explains that this could interfere with fertility by

preventing the sperm from swimming to the egg cell

The function of chloroplasts is

photosynthesis

A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. Which one of the following instruments would be best?

a scanning electron microscope

The nucleoid region of a prokaryotic cell

contains the cell's DNA.

Which of the following statements regarding the Golgi apparatus is false?

The Golgi apparatus decreases in size when a cell increases its protein production

The Golgi apparatus

stores, modifies, and packages proteins

Archaea are composed of ________ cells

prokaryotic

Which of the following cells has the greatest surface-to-volume ratio?

bacterium

The function of the nucleolus is

to manufacture ribosomal RNA.

Which of the following statements about internal membranes in eukaryotic cells is false?

In eukaryotic cells, internal membranes standardize the internal environment of all cellular organelles.

The two main functions of the rough endoplasmic reticulum are the production of

membrane and proteins secreted by the cell.

Which of the following statements regarding plasmodesmata is false?

Plasmodesmata are found in plants as well as some single-celled organisms

A basal body is

similar in structure to centrioles

A bacterial cell's DNA is found in its

nucleoid region

Resolution is the

ability of an optical instrument to show two close objects as separate.

Which of the following statements about cells is true?

All cells have internal structures that move.

Which of the following statements about electron microscopes is true

Electron microscopes focus electron beams to create a magnified image of an object.

Tay-Sachs disease

causes an accumulation of lipids in brain cells

Protein synthesis requires the use of mRNA, which

is translated by the ribosomes into the amino acid sequences of proteins

Light microscopes

use light and glass lenses to magnify an image.

A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they

have gained water and burst

A drug that interferes with microtubule formation is likely to completely disrupt

the movements of sperm cells

A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation

will eventually be problematic, since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs.

Cellular metabolism is the chemical activities of the cell.

t

Protein synthesis takes place in the vacuole

f

The nucleus is the genetic control center of a prokaryotic cell

f

The central vacuole is a membrane-enclosed sac occupying most of the interior of a mature animal cell

f

The extracellular matrix is the nonliving substance in which the cells of an animal tissue are embedded.

t

The diffuse, extended form of DNA when a cell is not dividing is called chromatin

t

An animal cell usually has a centrosome with a pair of centrioles involved in cell division.

t

A prokaryotic cell is lacking a membrane-bound nucleus

t

Chromosomes are most visible during mitosis and meiosis

t

The cell wall is a protective layer external to the plasma membrane

t

A flagellum is a long cellular appendage specialized for locomotion

t

The cell theory states that all living things are made up of cells and that cells come from other cells.

t

The nucleus is the genetic control center of a prokaryotic cell

f

A membrane-enclosed structure with a specialized function within a cell is called an organelle

t

Cellular metabolism is the chemical activities of the cell

t

The chromosome is the main gene-carrying structure, found in the nucleus, of a eukaryotic cell

t

An electron microscope magnifies 1,000,000 times more than a light microscope

f

The cell wall is a protective layer external to the plasma membrane.

t

The diffuse, extended form of DNA when a cell is not dividing is called chromatin

t

The semifluid medium in which the organells sit is called Cytosine

f

A short cellular appendage, called cilia, specialized for locomotion

t

A chloroplast is an organelle found in plants and photosynthetic protists

t

The cell theory states that all living things are made up of cells and that cells come from other cells

t

A prokaryotic cell is lacking a membrane-bound nucleus

t

ATP can be used as the cell's energy exchange mechanism because

endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP.

Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion?

exocytosis

In a hypotonic solution, an animal cell will

lyse

When physicians perform an organ transplant, they choose a donor whose tissues match those of the recipient as closely as possible. Which of the following cell components are being matched

cell-surface carbohydrates

Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell is called

signal transduction

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?

Na+

Living systems

decrease their entropy while increasing the entropy of the universe

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of

passive transport

Heating inactivates enzymes by

changing the enzyme's three-dimensional shape

In the lab, you use a special balloon that is permeable to water, but not sucrose, to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?

Water will leave the balloon.

Which characteristic promoted the utilization of lipids as the first cell membrane?

self-assembly into a simple membrane

Substrates bind to an enzyme's ________ site

active

Which of the following statements is true among all types of passive transport

The concentration gradient is the driving force.

Cells acquire LDLs by

receptor-mediated endocytosis

The cholesterol associated with animal cell membranes

helps to stabilize the cell membrane at body temperature

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction

exergonic . . . endergonic

A plant cell in a hypotonic solution

becomes turgid because of an inflow of water

In the reaction A → B + C + heat,

the potential energy of the products is less than that of the reactant.

Many of the enzymes that control a deep-sea firefly squid's ability to produce light energy from chemical energy are located

in membranes.

According to ________, energy cannot be created or destroyed

the first law of thermodynamics

Plasma membranes are selectively permeable. This means that

the plasma membrane allows some substances to enter or leave a cell more easily than others

The transfer of a phosphate group to a molecule or compound is called

phosphorylation

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment

hypotonic to the protozoan

Which of the following energy transfers is impossible in living systems

heat to light energy

The fluid mosaic model describes the plasma membrane as consisting of

diverse proteins embedded in a phospholipid bilayer

Osmosis can be defined as

the diffusion of water

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing

chemical energy into kinetic energy

Heating inactivates enzymes by

changing the enzyme's three-dimensional shape.

Which of the following statements about the ATP molecule is true?

It releases energy when one phosphate group leaves ATP

Small, nonpolar, hydrophobic molecules such as fatty acids

easily pass through a membrane's lipid bilayer

Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell is called

signal transduction

Which of the following statements regarding enzymes is true

Enzymes catalyze specific reactions

What is the basic difference between exergonic and endergonic reactions?

Exergonic reactions release energy; endergonic reactions absorb it.

A plant cell in a hypotonic solution

becomes turgid because of an inflow of water

Membrane phospholipids

are able to drift about in the plasma membrane

Which of the following processes is endergonic

the synthesis of glucose from carbon dioxide and water

Energy coupling is the use of energy produced during an exergonic to drive an endergonic reaction

t

Passive transport is the diffusion of a substance across a biological membrane, without the input of energy.

t

Facilitated diffusion requires a transport protein

t

An exergonic reaction releases the amount of energy equal to the difference in the potential energy between the reactants and products

t

Pinocytosis is the process of a cell taking fluids into via small membraneous vesicles.

t

Phagocytosis is when a cell engulfs macromolecules into its cytoplasm

t

Chemical energy is a form of potential energy

t

The energy of a mass of matter that is moving is called kenetic energy.

t

The energy matter possesses because of its location or arrangement is called Potential energy

t

The amount of energy that reactants must absorb before a chemical reaction can start is called endocytosis

f

Metabolic control that prevents the production an enzyme is called feedback inhibition

t

A competitive inhibitor’s structure mimics that of an enzyme’s substrate.